<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
</head>
<body>
<div class="jumbotron jumbotron-fluid text-center">
    <div class="container">
        <h1 class="display-4">Javascript ToDo</h1>
        <p class="lead">待办事项</p>
    </div>
</div>
<div class="container">
    <form class="md-5" action="" onsubmit="return false">
        <div class="form-group">
            <input id="ipt" type="text" class="form-control" placeholder="在此输入任务...">
        </div>
        <button id="btn" type="submit" class="btn btn-primary btn-block" style="width: 100%; margin-bottom: 20px">添加</button>
    </form>
    <ul class="list-group" id="ul"></ul>
</div>

<script src="js/script.js"></script>
</body>
</html>